Mimosine synthesis

Ikegami, R, Mizuno, M. and Murakoshi, I. (1990) Enzymatic synthesis of the thyrotoxic amino acid, mimosine, by cysteine synthase. Phytochemistry, 29,3461-6. 

The procedure given here describes the preparation and use of N-(benzyloxycarbonyl)-L-serine p-lactone for the synthesis of a protected -substituted alanine, N - benzyloxycarbonyl)-P—(pyrazol-l-yl)-L-alanine. This compound occurs in watermelon seeds,9 and has been used as a histidine analog.Its synthesis illustrates how serine p-lactones can provide convenient access to other p-substituted alanines such as mimosine, willardiine, quisqualic acid, and stizolobic add which occur in higher plants.5a,io Many previous chemical syntheses of racemic pyrazolylalanine have been published the best of these routes appear to be from acetamidoacryiic acid (94-96% yield) and from 0-acetylserine (40-45%).The... 

There are several others that inhibit DNA replication. Fagaronine and nitidine have ben mentioned previously as intercalating agents, and this intercalation evidently inhibits the action of DNA polymerase [334]. Several benzophenanthridines and protoberberines inhibit reverse transcriptase, which catalyzes the synthesis of DNA with an RNA template [356, 357]. Mimosine at the cellular level, rather than directly on the process, is an inhibitor of DNA synthesis because it chelates iron [358] and because it blocks the synthesis of thymidylate, an essential precursor of DNA [359]. Vincristine may also act as an inhibitor of thymidylate synthesis, perhaps because it alkylates an essential thiol group of an enzyme [360]. 

The elimination-addition pathway proposed for the epoxidation reaction in the synthesis of flavipucine has been challenged on the grounds that this mechanism has not been established unequivocally. Sesbanine is a novel cytotoxic alkaloid occurring in the seeds of Sesbania drummondiv, its constitution (48) has been settled by spectral study and by X-ray diffraction analysis. Several amino-substituted derivatives of mimosine, (possible inhibitors of the growth of wool) have been synthesized. ... 

Activity toxicity M. is a powerful inhibitor of cystathionine synthase and cystathionase. The growth of shoots of Phaseolus aureus is inhibited by 3,4-dihy-droxypyridine and mimosine with equal activity. The inhibitory activity is neutralised by addition of pyri-doxal phosphate. M. causes loss of hair in sheep, horses, and pigs goats and cattle, in contrast, are not affected in this way. M. effects growing hair, impairs the estrogen cycle in rats, and DNA synthesis. ... 

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